DOCSLIB.ORG

Paleomagnetism of Early Paleozoic Rocks of the De

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Paleomagnetism of Early Paleozoic Rocks of the De PALEOMAGNETISM OF EARLY PALEOZOIC ROCKS OF THE DE LONG ARCHIPELAGO AND TECTONICS OF THE NEW SIBERIAN ISLANDS TERRANE Metelkin D.V., Chernova A.I, Trofimuk Institute of Petroleum Geology and Geophysics SB RAS Matushkin N.Yu., Vernikovsky V.A. [email protected] Novosibirsk State University Novosibirsk, Russia Paleotectonic reconstructions for 520-440 Ma Abstract 520 Ma Jeannette Island North NSI South The De Long archipelago is located to the north of the Anjou archipelago as a part of a Paleoasian30 O ocean hemisphere hemisphere 30 O large group between the Laptev Sea Bennett Island and Henrietta Island, the New Siberian OM Paleoasian ocean . Islands and consists of Jeannette Island– and the East Siberian Sea tTwhose tectonic history was independent of other, hese islands have been shown CH CH Siberia Siberia o be part of a single continental terrane Paleomagnetic and precise geological data for the De Long equator equator De Long archipelago were. continental masses at least since the Ordovician special inter Archipelago nnational field trips to the De Long Islands could be organized and geological???? Only i NSI OM Laurentia . absent until recently, geochronological and paleomagnetic studies were carried out-isot Kara Laurentia Kara .ope Baltica 30 30 O O Iapetus ocean Baltica aOThe age of these dikes is more. sedimentary sequence intruded by mafic dikes w Svalbard New Siberian Islands Svalbard s described-n Jeannette Island a volcanic Ar and paleomagnetic investigations of the/ a Iapetus ocean s evidenced by the results of our Ar, Ma48? close to , likely Early Ordovician there are wid 60 O 60 eespread, On Bennett Island. dolerites as well as the result from detrital zircons in th Bennett Island O Gondwana host rocks published before Paleomagnetic results from these rocks characterize the pale Gondwana ogeographic. Ordovician mainly terrigenous rocks-Cambrian although there is no evi ndence for the primary origin of, Ma5?? Ma and perhaps at 465 position of the De Lo g archipelago at A. sedimentary section was investigated-On Henrietta Island the Early 480 Ma Cambrian volcanic. magnetization for the latter Adding to our previous paleomagnet ic. Ar results/ Ma was obtained and confirmed by new Ar5?? paleomagnetic pole for data NSI for the Anjou archipelago the extended variant of the apparent polar wander path for the OM 30 30 O New Siberian Island terrane was degrees4? The established paleolatitudes define its O Paleoasian ocean Paleoasian ocean location in the equatorial and subtropical zone no higher than . created Because there are CH u no good confirmations for true polarity and related geographic hemisphere we. d Henrietta Island CH ring the Early Paleozoic But both these solutions demonstrate a very close paleogeographi equator Siberia Siberia c position. present two possibilities for tectonic reconstruction between the New Siberian Laurentia equator Laurentia .Island and the Siberian continent The study was supported by Ministry of Education and Science of the Russian Federation Iapetus ocean OM Kara Kara (5????4????7grant No ), RSF (grant ?4-?7-?????No ), RFBR (?5-?5-??4?8grant No ). Iapetus ocean NSI 30 O Svalbard Svalbard 30 O Rheic ocean Rheic ocean Geological maps of Bennett, Henrietta and Jeannette158 IslandsO00’ E Baltica O O O Table. Mean paleomagnetic directions, paleomagnetic poles coordinates and paleolatitudes based on 149 00' E 149 20’ 156O26’ E 156 39’ E. Baltica 60 O QIV 2 km paleomagnetic study of Early Paleozoic archipelagos Anjou and De Long, which used for the NSI 60 ˆ 1 Jeannette Is. O Polar st. Dyunbar cape N Porphyric diorite and QIV Henrietta Is. APWP Bennett Is. K1 Pz tg subvolcanic basalts O 1 km 2-3 45 1-2 2 O Pavel Keppen Objects, Geographic coordinates Stratigraphic coordinates Paleomagnetic poles Gondwana Gondwana 75 43' K1 Unexplored area Plat K Basalts ? n/N N 1 bay Bennetta cape age O O D I k a95 D I k a95 PLat PLong A95 2 2 3 O 65 1-2 Tuffaceous gravelites, Q 60 Koteny Is., limestones 43/45 440 Ma O IV K 1 208.3 81.5 87.0 9.9 272.0 53.9 558.5 3.9 33.7 55.7 5.1 34.4 60 1 4 50 sandstones 13NS01 36 (4) 11NS10 76O47’ N 440 Ma 13NS02 34 11NS11 70 K1 25 Tuffaceous siltstones Paleopacific 41 Bennett Is., sandstones 25/33 K Pz2-3bz 72 Paleopacific 11NS12 1 5 13NS03 2 298.5 54.1 109.3 11.9 307.7 57.4 178.4 9.3 45.5 31.9 11.0 38.0 Zeeberg Glacier 5 45 465 Ma (3) 30 Quartz and polymictic 35 40 NSI O K Pz2-3tg 31 1 Q 42 30 O 30 IV 6 17 sandstones, shales 1 km Kotelny Is., dolomites 23/25 3 278.3 77.5 25.7 51.4 315.6 59.1 414.0 12.3 48.9 13.8 18.1 39.9 (2) O 13NS12 18 475 Ma 75 40' O 13NS04 dolerite dykes OM 13NS10 1-2 Pz kp unit 1, volcanogenic-clastic turbidites, Chernyshev 7 1 13NS05 dolerite dikes 13NS11 sandstones, gravelstones, tuffs; Jeannette Is., dolerites, 39/45 36.5 CH pen. Pz bz Pz1ta 4 308.7 44.8 55.5 16.7 344.4 56.0 468.7 5.7 49.2 357.4 5.9 CH 1 13NS07 480 Ma (3) Siberia 8 13NS08 thrusts faults: Siberia O2 ˆ QIV 13NS06 unit 2, mainly tuff breccias; Pz ta N of uncertain kinematics (a), Henrietta Is., sandstones, ˆ 18 2-3 b O2 K Pz2-3tg 56/65 1 a c upthrow-thrust kinematics (b) 5 tuffs, basalts 294.5 25.4 19.0 14.2 295.5 34.0 282.0 3.6 23.7 45.7 3.2 18.6 10 paleomagnetic (6) Sophia cape unit 3, volcanogenicclastic 520 Ma Paleoasian ocean PaleoasianKazakhstan ocean sample sites inferred faults (c); Kazakhstan 11 6 8 turbidites and tuff breccias; Kara equator 1 – Cambrian deposits; 2–3 – Ordovician deposits; 4 – Cretaceous 3 Kara equator 70 50 Pz kp 12 Bennett Is., sandstones 18/22 deposits; 5 – Cretaceous basaltic covers; 6 – Paleogene- 1 13NS09 unit 4, coarse-grained volcanogenic paleomagnetic 6 (2) 247.8 46.5 184.3 18.5 249.2 37.0 265.1 15.4 15.5 83.6 18.0 20.6 O 530 Ma Quaternary deposits; 7 – fauna findings; 8 – paleomagnetic 156 39’ E -clastic turbidites; sample sites Svalbard sampling sites. Svalbard Laurentia OM Paleomagnetic study results Laurentia Uralic ocean NSI Uralic ocean Site 13NS07 APWP for NSI terrane Baltica Site 13NS04 Site 13NS01 Baltica O Site 11NS11 N,UP N UP N UP N N,N 30 O 30 N Upper N Upper Upper N Upper Lower Lower Iapetus ocean Lower Lower 630 °C 120 mT Mean paleomagnetic directions NRM ChRM 1213 600°C New Siberian Islands (NSI) Rheic ocean N Rheic ocean NRM NRM Upper NRM ChRM Lower 400 °Ñ ChRM 60 O [Vernikovsky et al., 2013, Middle Lower-Middle 60 Lower NRM Metelkin et al., 2016] Laurentia Cambrian O Ordovician Upper [Cocks, Torsvik, 2011] 250 Gondwana Gondwana Sample 11NS141 E,E Sample 13NS054 E 250 630 °C 360°Ñ 475 270 Upper Ordovician- Bazalt E Sandstone 400 °Ñ 480 270 Lower Silurian 465 290 Mmax= 55.6 mA/m Sample 13NS085b Mmax=0.24 ìA/ì 460 °C E Mmax= 266 mA/m Mmax=0.69 ìA/ì Paleotectonic reconstruction in which two possible scenarios of NSI terrane position in the Early Paleozoic are presented: on top - N-scenario 1 1 1 1 Lower Cambrian Tuff E Sample 13NS011 440 310 120 mT E,UP for nothern hemisphere, on bottom - S-scenario for southern hemisphere. NSI - New Siberian Islands terrane, OM- Omulevka terrane, CH - 600°C Tilt Dolerite 320 440 corrected 9 mT 370 Chukchi-Alaska terrane. 180 °C [Zhdanova et al., 2016] 470 460 350 N-scenario supposes the normal polarity of geomagnetic field while rocks forming and placing the NSI terrane in the northen hemisphere. Such M/Mmax NSI 520 M/Mmax M/Mmax NRM M/Mmax 490 ChRM 405 Sample 13NS085b 530 400 an option is advantageous because of the minimum horizontal displacements of the terrane resulting from the analysis of the entire set of NRM 515 Equator NRM 430 400 °Ñ 0 0 paleomagnetic data. At the other hand, in this case in the Early Cambrian it should be over a significant distance from Verkhoyansk margin of 0 60 120 mT 0 200 0 315 630 °C 0 300 600 °C [Chernova et al., 2017] 440 530 Baltica [Torsvik et al., 2012] Siberia with which there was a obvious biogeographic link at that time. We assume that this space could be occupied by Omulevka and probably Upper Site 13NS11 W,UP Upper N N UP Upper Site 13NS09 N UP N Site 13NS02 Upper N Preliminary, not published results 450 Lower Site 13NS05 Lower Lower N,N Lower Chukchi-Alaska continental terranes which enabled the fauna to migrate along the shelf. In the Ordovician it is supposed the disintegration this (Bennett Islands Cambrian sandstones) 460 NRM 470 system and further convergence with the Siberia. The downside of this model is that such NSI position is to far from Baltic which is supposed as NRM 540 500 NRM 500 a main provenance area of detrital zircons (Ershova et al., 2016) and this fact should be sought for another explanation. ChRM 600°C Siberia 1 Poles for De Long Islands [Cocks,Torsvik, 2007] 520 The second variant (S-scenario) assumes a more typical for the early Paleozoic reverse polarity of the geomagnetic field and the southern NRM NRM Poles for Anjou Islands 520 80 mT position of the NSI terrane.
Load more

Recommended publications
  • North America Other Continents
    Arctic Ocean Europe North Asia America Atlantic Ocean Pacific Ocean Africa Pacific Ocean South Indian America Ocean Oceania Southern Ocean Antarctica LAND & WATER • The surface of the Earth is covered by approximately 71% water and 29% land. • It contains 7 continents and 5 oceans. Land Water EARTH’S HEMISPHERES • The planet Earth can be divided into four different sections or hemispheres. The Equator is an imaginary horizontal line (latitude) that divides the earth into the Northern and Southern hemispheres, while the Prime Meridian is the imaginary vertical line (longitude) that divides the earth into the Eastern and Western hemispheres. • North America, Earth’s 3rd largest continent, includes 23 countries. It contains Bermuda, Canada, Mexico, the United States of America, all Caribbean and Central America countries, as well as Greenland, which is the world’s largest island. North West East LOCATION South • The continent of North America is located in both the Northern and Western hemispheres. It is surrounded by the Arctic Ocean in the north, by the Atlantic Ocean in the east, and by the Pacific Ocean in the west. • It measures 24,256,000 sq. km and takes up a little more than 16% of the land on Earth. North America 16% Other Continents 84% • North America has an approximate population of almost 529 million people, which is about 8% of the World’s total population. 92% 8% North America Other Continents • The Atlantic Ocean is the second largest of Earth’s Oceans. It covers about 15% of the Earth’s total surface area and approximately 21% of its water surface area.
    [Show full text]
  • New Constraints on the Age, Geochemistry
    New constraints on the age, geochemistry, and environmental impact of High Arctic Large Igneous Province magmatism: Tracing the extension of the Alpha Ridge onto Ellesmere Island, Canada T.V. Naber1,2, S.E. Grasby1,2, J.P. Cuthbertson2, N. Rayner3, and C. Tegner4,† 1 Geological Survey of Canada–Calgary, Natural Resources Canada, Calgary, Canada 2 Department of Geoscience, University of Calgary, Calgary, Canada 3 Geological Survey of Canada–Northern, Natural Resources Canada, Ottawa, Canada 4 Centre of Earth System Petrology, Department of Geoscience, Aarhus University, Aarhus, Denmark ABSTRACT Island, Nunavut, Canada. In contrast, a new Province (HALIP), is one of the least studied U-Pb age for an alkaline syenite at Audhild of all LIPs due to its remote geographic lo- The High Arctic Large Igneous Province Bay is significantly younger at 79.5 ± 0.5 Ma, cation, and with many exposures underlying (HALIP) represents extensive Cretaceous and correlative to alkaline basalts and rhyo- perennial arctic sea ice. Nevertheless, HALIP magmatism throughout the circum-Arctic lites from other locations of northern Elles- eruptions have been commonly invoked as a borderlands and within the Arctic Ocean mere Island (Audhild Bay, Philips Inlet, and potential driver of major Cretaceous Ocean (e.g., the Alpha-Mendeleev Ridge). Recent Yelverton Bay West; 83–73 Ma). We propose anoxic events (OAEs). Refining the age, geo- aeromagnetic data shows anomalies that ex- these volcanic occurrences be referred to col- chemistry, and nature of these volcanic rocks tend from the Alpha Ridge onto the northern lectively as the Audhild Bay alkaline suite becomes critical then to elucidate how they coast of Ellesmere Island, Nunavut, Canada.
    [Show full text]
  • A Newly Discovered Glacial Trough on the East Siberian Continental Margin
    Clim. Past Discuss., doi:10.5194/cp-2017-56, 2017 Manuscript under review for journal Clim. Past Discussion started: 20 April 2017 c Author(s) 2017. CC-BY 3.0 License. De Long Trough: A newly discovered glacial trough on the East Siberian Continental Margin Matt O’Regan1,2, Jan Backman1,2, Natalia Barrientos1,2, Thomas M. Cronin3, Laura Gemery3, Nina 2,4 5 2,6 7 1,2,8 9,10 5 Kirchner , Larry A. Mayer , Johan Nilsson , Riko Noormets , Christof Pearce , Igor Semilietov , Christian Stranne1,2,5, Martin Jakobsson1,2. 1 Department of Geological Sciences, Stockholm University, Stockholm, 106 91, Sweden 2 Bolin Centre for Climate Research, Stockholm University, Stockholm, Sweden 10 3 US Geological Survey MS926A, Reston, Virginia, 20192, USA 4 Department of Physical Geography (NG), Stockholm University, SE-106 91 Stockholm, Sweden 5 Center for Coastal and Ocean Mapping, University of New Hampshire, New Hampshire 03824, USA 6 Department of Meteorology, Stockholm University, Stockholm, 106 91, Sweden 7 University Centre in Svalbard (UNIS), P O Box 156, N-9171 Longyearbyen, Svalbard 15 8 Department of Geoscience, Aarhus University, Aarhus, 8000, Denmark 9 Pacific Oceanological Institute, Far Eastern Branch of the Russian Academy of Sciences, 690041 Vladivostok, Russia 10 Tomsk National Research Polytechnic University, Tomsk, Russia Correspondence to: Matt O’Regan ([email protected]) 20 Abstract. Ice sheets extending over parts of the East Siberian continental shelf have been proposed during the last glacial period, and during the larger Pleistocene glaciations. The sparse data available over this sector of the Arctic Ocean has left the timing, extent and even existence of these ice sheets largely unresolved.
    [Show full text]
  • Kenya | Year 2| Important Questions Key Knowledge Vocabulary 1 Where Is Kenya on a a Large Solid Area of Land
    Kenya | Year 2| Important Questions Key Knowledge Vocabulary 1 Where is Kenya on a A large solid area of land. Earth has Kenya is in East Africa. Nairobi is the 1 continent world map? seven continents. capital city and Mombasa is the largest An area set aside by a country’s 2 What is life like for city in Kenya. 2 National people living in Kenya? park government. The Tana river is the longest river in 3 Maasai one of the best-known groups of 3 What is a national Kenya. people in Africa. They live in park? southern Kenya Mount Kenya is the highest mountain in 4 Endangered Any type of plant or animal that is 4 Which are the main Kenya. in danger of disappearing forever. animals living in Kenya? 5 migrate Many mammals, birds, fishes, 5 What is Maasai insects, and other animals move culture? Kenya lies on the Equator, which means from one place to another at the climate is hot, sunny and dry for most certain times of the year. What is life like for a 6 of the year. ocean A large body of salt water, which Kenyan child compared 6 The Great Rift Valley is an enormous covers the majority of the earth’s to my life? valley of mountains which runs from the surface. north to south of Kenya. The valley has a 7 Capital A large town. Each country has a chain of volcanoes which are still ‘active’ . city capital city, which is usually one of Lake Victoria, the second largest the largest cities.
    [Show full text]
  • Paleozoic Rocks of Northern Chukotka Peninsula, Russian Far East: Implications for the Tectonicsof the Arctic Region
    TECTONICS, VOL. 18, NO. 6, PAGES 977-1003 DECEMBER 1999 Paleozoic rocks of northern Chukotka Peninsula, Russian Far East: Implications for the tectonicsof the Arctic region BorisA. Natal'in,1 Jeffrey M. Amato,2 Jaime Toro, 3,4 and James E. Wright5 Abstract. Paleozoicrocks exposedacross the northernflank of Alaskablock the essentialelement involved in the openingof the the mid-Cretaceousto Late CretaceousKoolen metamorphic Canada basin. domemake up two structurallysuperimposed tectonic units: (1) weaklydeformed Ordovician to Lower Devonianshallow marine 1. Introduction carbonatesof the Chegitununit which formed on a stableshelf and (2) strongly deformed and metamorphosedDevonian to Interestin stratigraphicand tectoniccorrelations between the Lower Carboniferousphyllites, limestones, and an&site tuffs of RussianFar East and Alaska recentlyhas beenrevived as the re- the Tanatapunit. Trace elementgeochemistry, Nd isotopicdata, sult of collaborationbetween North Americanand Russiangeol- and texturalevidence suggest that the Tanataptuffs are differen- ogists.This paperpresents the resultsof one suchstudy from the tiatedcalc-alkaline volcanic rocks possibly derived from a mag- ChegitunRiver valley, Russia,where field work was carriedout matic arc. We interpretthe associatedsedimentary facies as in- to establishthe stratigraphic,structural, and metamorphicrela- dicativeof depositionin a basinal setting,probably a back arc tionshipsin the northernpart of the ChukotkaPeninsula (Figure basin. Orthogneissesin the core of the Koolen dome yielded a
    [Show full text]
  • Evidence for Slab Material Under Greenland and Links to Cretaceous
    PUBLICATIONS Geophysical Research Letters RESEARCH LETTER Evidence for slab material under Greenland 10.1002/2016GL068424 and links to Cretaceous High Key Points: Arctic magmatism • Mid-mantle seismic and gravity anomaly under Greenland identified G. E. Shephard1, R. G. Trønnes1,2, W. Spakman1,3, I. Panet4, and C. Gaina1 • Jurassic-Cretaceous slab linked to paleo-Arctic ocean closure, prior to 1Centre for Earth Evolution and Dynamics (CEED), Department of Geosciences, University of Oslo, Oslo, Norway, 2Natural Amerasia Basin opening 3 • Possible arc-mantle signature in History Museum, University of Oslo, Oslo, Norway, Department of Earth Sciences, Utrecht University, Utrecht, Netherlands, 4 Cretaceous High Arctic LIP volcanism Institut National de l’Information Géographique et Forestière, Laboratoire LAREG, Université Paris Diderot, Paris, France Supporting Information: Abstract Understanding the evolution of extinct ocean basins through time and space demands the • Supporting Information S1 integration of surface kinematics and mantle dynamics. We explore the existence, origin, and implications Correspondence to: of a proposed oceanic slab burial ground under Greenland through a comparison of seismic tomography, G. E. Shephard, slab sinking rates, regional plate reconstructions, and satellite-derived gravity gradients. Our preferred [email protected] interpretation stipulates that anomalous, fast seismic velocities at 1000–1600 km depth imaged in independent global tomographic models, coupled with gravity gradient perturbations, represent paleo-Arctic oceanic slabs Citation: that subducted in the Mesozoic. We suggest a novel connection between slab-related arc mantle and Shephard, G. E., R. G. Trønnes, geochemical signatures in some of the tholeiitic and mildly alkaline magmas of the Cretaceous High Arctic W.
    [Show full text]
  • Aerosol Optical Depth and Direct Radiative Forcing for INDOEX Derived from AVHRR: Observations, January–March 1996–2000 William R
    JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 107, NO. D19, 8010, 10.1029/2000JD000183, 2002 Aerosol optical depth and direct radiative forcing for INDOEX derived from AVHRR: Observations, January–March 1996–2000 William R. Tahnk and James A. Coakley Jr. College of Oceanic and Atmospheric Sciences, Oregon State University, Corvallis, Oregon, USA Received 20 November 2000; revised 13 July 2001; accepted 12 November 2001; published 20 August 2002. [1] Visible and near infrared reflectances from NOAA-14 Advanced Very High Resolution Radiometer (AVHRR) daytime passes are used to derive optical depths at 0.55 mm, an index of aerosol type, continental or marine, and the direct effect of the aerosol on the top of the atmosphere and surface solar radiative fluxes for the oceans in the Indian Ocean Experiment (INDOEX) region (30°Sto30°N and 50°–110°E) during the January–March 1996–2000 winter monsoons. Comparison of aerosol optical depth and radiative forcing in the Northern Hemisphere with those in the Southern Hemisphere suggests that the additional pollution sources augment the 0.55-mm optical depth by, on average, 0.1 in the Northern Hemisphere. As a result of the aerosol, the region of the Indian Ocean in the Northern Hemisphere loses about 1.6 WmÀ2 in reflected sunlight and the ocean surface loses about 5 WmÀ2 during the months of the winter monsoon. Aerosol burdens and the aerosol direct radiative forcing are a relatively constant feature of the Northern Hemisphere, although the southeastern Arabian Sea experienced considerably larger aerosol burdens during the February–March 1999 INDOEX Intensive Field Phase (IFP) than in other years.
    [Show full text]
  • Coriolis Effect
    Project ATMOSPHERE This guide is one of a series produced by Project ATMOSPHERE, an initiative of the American Meteorological Society. Project ATMOSPHERE has created and trained a network of resource agents who provide nationwide leadership in precollege atmospheric environment education. To support these agents in their teacher training, Project ATMOSPHERE develops and produces teacher’s guides and other educational materials. For further information, and additional background on the American Meteorological Society’s Education Program, please contact: American Meteorological Society Education Program 1200 New York Ave., NW, Ste. 500 Washington, DC 20005-3928 www.ametsoc.org/amsedu This material is based upon work initially supported by the National Science Foundation under Grant No. TPE-9340055. Any opinions, findings, and conclusions or recommendations expressed in this publication are those of the authors and do not necessarily reflect the views of the National Science Foundation. © 2012 American Meteorological Society (Permission is hereby granted for the reproduction of materials contained in this publication for non-commercial use in schools on the condition their source is acknowledged.) 2 Foreword This guide has been prepared to introduce fundamental understandings about the guide topic. This guide is organized as follows: Introduction This is a narrative summary of background information to introduce the topic. Basic Understandings Basic understandings are statements of principles, concepts, and information. The basic understandings represent material to be mastered by the learner, and can be especially helpful in devising learning activities in writing learning objectives and test items. They are numbered so they can be keyed with activities, objectives and test items. Activities These are related investigations.
    [Show full text]
  • 1 Climatology of South American Seasonal Changes
    Vol. 27 N° 1 y 2 (2002) 1-30 PROGRESS IN PAN AMERICAN CLIVAR RESEARCH: UNDERSTANDING THE SOUTH AMERICAN MONSOON Julia Nogués-Paegle 1 (1), Carlos R. Mechoso (2), Rong Fu (3), E. Hugo Berbery (4), Winston C. Chao (5), Tsing-Chang Chen (6), Kerry Cook (7), Alvaro F. Diaz (8), David Enfield (9), Rosana Ferreira (4), Alice M. Grimm (10), Vernon Kousky (11), Brant Liebmann (12), José Marengo (13), Kingste Mo (11), J. David Neelin (2), Jan Paegle (1), Andrew W. Robertson (14), Anji Seth (14), Carolina S. Vera (15), and Jiayu Zhou (16) (1) Department of Meteorology, University of Utah, USA, (2) Department of Atmospheric Sciences, University of California, Los Angeles, USA, (3) Georgia Institute of Technology; Earth & Atmospheric Sciences, USA (4) Department of Meteorology, University of Maryland, USA, (5) Laboratory for Atmospheres, NASA/Goddard Space Flight Center, USA, (6) Department of Geological and Atmospheric Sciences, Iowa State University, USA, (7) Department of Earth and Atmospheric Sciences, Cornell University, USA, (8) Instituto de Mecánica de Fluidos e Ingeniería Ambiental, Universidad de la República, Uruguay, (9) NOAA Atlantic Oceanographic Laboratory, USA, (10) Department of Physics, Federal University of Paraná, Brazil, (11) Climate Prediction Center/NCEP/NWS/NOAA, USA, (12) NOAA-CIRES Climate Diagnostics Center, USA, (13) Centro de Previsao do Tempo e Estudos de Clima, CPTEC, Brazil, (14) International Research Institute for Climate Prediction, Lamont Doherty Earth Observatory of Columbia University, USA, (15) CIMA/Departmento de Ciencias de la Atmósfera, University of Buenos Aires, Argentina, (16) Goddard Earth Sciences Technology Center, University of Maryland, USA. (Manuscript received 13 May 2002, in final form 20 January 2003) ABSTRACT A review of recent findings on the South American Monsoon System (SAMS) is presented.
    [Show full text]
  • Redacted for Privacy Abstract Approved: John V
    AN ABSTRACT OF THE THESIS OF MIAH ALLAN BEAL for the Doctor of Philosophy (Name) (Degree) in Oceanography presented on August 12.1968 (Major) (Date) Title:Batymety and_Strictuof_thp..4rctic_Ocean Redacted for Privacy Abstract approved: John V. The history of the explordtion of the Central Arctic Ocean is reviewed.It has been only within the last 15 years that any signifi- cant number of depth-sounding data have been collected.The present study uses seven million echo soundings collected by U. S. Navy nuclear submarines along nearly 40, 000 km of track to construct, for the first time, a reasonably complete picture of the physiography of the basin of the Arctic Ocean.The use of nuclear submarines as under-ice survey ships is discussed. The physiography of the entire Arctic basin and of each of the major features in the basin are described, illustrated and named. The dominant ocean floor features are three mountain ranges, generally paralleling each other and the 40°E. 140°W. meridian. From the Pacific- side of the Arctic basin toward the Atlantic, they are: The Alpha Cordillera; The Lomonosov Ridge; andThe Nansen Cordillera. The Alpha Cordillera is the widest of the three mountain ranges. It abuts the continental slopes off the Canadian Archipelago and off Asia across more than550of longitude on each slope.Its minimum width of about 300 km is located midway between North America and Asia.In cross section, the Alpha Cordillera is a broad arch rising about two km, above the floor of the basin.The arch is marked by volcanoes and regions of "high fractured plateau, and by scarps500to 1000 meters high.The small number of data from seismology, heat flow, magnetics and gravity studies are reviewed.The Alpha Cordillera is interpreted to be an inactive mid-ocean ridge which has undergone some subsidence.
    [Show full text]
  • Laptev Sea System
    Russian-German Cooperation: Laptev Sea System Edited by Heidemarie Kassens, Dieter Piepenburg, Jör Thiede, Leonid Timokhov, Hans-Wolfgang Hubberten and Sergey M. Priamikov Ber. Polarforsch. 176 (1995) ISSN 01 76 - 5027 Russian-German Cooperation: Laptev Sea System Edited by Heidemarie Kassens GEOMAR Research Center for Marine Geosciences, Kiel, Germany Dieter Piepenburg Institute for Polar Ecology, Kiel, Germany Jör Thiede GEOMAR Research Center for Marine Geosciences, Kiel. Germany Leonid Timokhov Arctic and Antarctic Research Institute, St. Petersburg, Russia Hans-Woifgang Hubberten Alfred-Wegener-Institute for Polar and Marine Research, Potsdam, Germany and Sergey M. Priamikov Arctic and Antarctic Research Institute, St. Petersburg, Russia TABLE OF CONTENTS Preface ....................................................................................................................................i Liste of Authors and Participants ..............................................................................V Modern Environment of the Laptev Sea .................................................................1 J. Afanasyeva, M. Larnakin and V. Tirnachev Investigations of Air-Sea Interactions Carried out During the Transdrift II Expedition ............................................................................................................3 V.P. Shevchenko , A.P. Lisitzin, V.M. Kuptzov, G./. Ivanov, V.N. Lukashin, J.M. Martin, V.Yu. ßusakovS.A. Safarova, V. V. Serova, ßvan Grieken and H. van Malderen The Composition of Aerosols
    [Show full text]
  • LATE PLEISTOCENE and EARLY HOLOCENE WINTER AIR TEMPERATURES in KOTELNY ISLAND: RECONSTRUCTIONS USING STABLE ISOTOPES of ICE WEDGES Yu.K
    Kriosfera Zemli, 2019, vol. XXIII, No. 2, pp. 12–24 http://www.izdatgeo.ru DOI: 10.21782/EC2541-9994-2019-2(12-24) LATE PLEISTOCENE AND EARLY HOLOCENE WINTER AIR TEMPERATURES IN KOTELNY ISLAND: RECONSTRUCTIONS USING STABLE ISOTOPES OF ICE WEDGES Yu.K. Vasil’chuk1,2, V.M. Makeev3, A.A. Maslakov1, N.A. Budantseva1, A.C. Vasil’chuk1 1 Lomonosov Moscow State University, Faculty of Geography and Faculty of Geology, 1, Leninskie Gory, Moscow, 119991, Russia 2 Tyumen State University, 6, Volodarskogo str., Tyumen, 625003, Russia; [email protected] 3Russian State Hydrometeorological University, 98, Malookhtinsky prosp., St. Petersburg, 109017, Russia Late Pleistocene and Holocene winter air temperatures in Kotelny Island, northeastern Russian Arctic, have been reconstructed using oxygen isotope compositions of ice wedges and correlated with evidence of Late Pleistocene and Holocene climate variations inferred from pollen data. The δ18О values range exceeds 6 ‰ in Late Pleistocene ice wedges but is only 1.5 ‰ in the Holocene ones (–30.6 ‰ to –24.0 ‰ against –23.1 ‰ to –21.6 ‰, respectively). The Late Pleistocene mean January air temperatures in Kotelny Island were 10–12 °С lower than the respective present temperature. On the other hand, mean winter temperatures in cold substages during the Karga interstadial were colder than those during the Sartan glacial event. The Late Pleistocene– Holocene climate history included several warm intervals when air temperatures were high enough to maintain the existence of low canopy tree patches in Kotelny Island. Mean January air temperatures in the early Holocene were only 1.0–1.5 °С lower than now.
    [Show full text]